本机查询上的Mockito NullPointerException [英] Mockito NullPointerException on Native Query

问题描述

我的查询对象有问题，即使我使用查询模拟对象对它进行存根，它也会变为null.这是代码

I am having a problem on my query object, it becomes null even though I stub it with a query mock object.. This is the code

Query query = getEntityManager().createNativeQuery(queryString, SomeRandom.class);

return query.getResultList(); //-->This is where I get the error, the query object is null.

我的测试方法是

Query query = mock(Query.class);
when(entityManager.createNativeQuery("", SomeRandom.class)).thenReturn(query);
List<SomeRandom> someList = requestDao.getSomeList(parameter, parameter, parameter, parameter);

推荐答案

这可能意味着您传递给模拟方法的匹配器之一不匹配.您传递了一个实际的 String 实例(空字符串)，该实例在后台转换为

This probably means that one of the matchers that you passed to the mocked method did not match. You passed an actual String instance (the empty string), which is transformed under the hood into an Equals matcher. Your example would only work if queryString was the empty string as well.

这应该与任何查询字符串匹配:

This should match on any query string:

when(entityManager.createNativeQuery(anyString(), eq(SomeRandom.class)))
  .thenReturn(query);

这是您希望传递的一些具体字符串上的内容:

And this on some concrete String that you expect to be passed:

String expectedQueryString = "select 1";

when(entityManager.createNativeQuery(expectedQueryString, SomeRandom.class))
  .thenReturn(query);

根据评论进行

如果从 eq(SomeRandom.class)更改为 any()可以解决问题，则 eq(SomeRandom.class)匹配器不匹配，这意味着 SomeRandom.class 实际上不是传递给模拟方法的内容.

If changing from eq(SomeRandom.class) to any() solved the problem, then the eq(SomeRandom.class) matcher did not match, which means SomeRandom.class was not what was in fact passed to the mocked method.

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